http://irgu.unigoa.ac.in/drs/handle/unigoa/3 Tue, 07 Apr 2026 09:47:37 GMT 2026-04-07T09:47:37Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7818 Metagenomic studies reveal diverse microbial community in the developmental stages of highly adaptable malarial vector Anopheles stephensi liston Pereira, M.H.; Tyagi, S.; Mohanty, A.; Garg, S.; Ashwani Kumar Anopheles stephensi, a highly adaptable malaria vector species, continues to expand its range from South Asia to Sub-Saharan Africa, posing a serious global public health concern. In India, it serves as the principal urban vector of both Plasmodium falciparum and P. vivax. Conventional control measures reliant on chemical insecticides have raised issues of resistance, highlighting the need for alternative strategies such as microbiota-mediated vector control. This study aimed to test the hypothesis that a subset of bacterial taxa persist across developmental stages of An. stephensi, representing potential candidates for transstadial transmission and future paratransgenic manipulation. Using both culture-based data and next-generation sequencing (NGS) approaches targeting the 16 S rRNA gene (V3-V4 region), we characterized bacterial communities from breeding water, larvae, pupae, and adult mosquitoes (male and female) collected in Goa, India. Across all developmental stages, Proteobacteria and Firmicutes were the dominant phyla, while 15 bacterial genera formed the putative core microbiome shared by greater than or equal to 80 percent of stages at greater than or equal to 0.1 percent abundance. Among these, Pseudomonas (adult males: 11.5 percent, pupae: 3.2 percent), Exiguobacterium, Acinetobacter, Psychrobacter, and Asticcacaulis were consistently detected, together contributing approximately 30 percent of total microbial composition. Alpha diversity indices indicated higher richness and evenness in pupae and adults than in larvae, suggesting microbial enrichment during metamorphosis. Beta diversity and PCoA analyses clustered pupal and adult stages distinctly from larvae and breeding water, confirming selective microbial retention through development. These findings reveal that An. stephensi harbors a stable, stage-spanning core microbiome dominated by metabolically versatile genera with potential for transstadial persistence. The dominance of Pseudomonas across life stages supports its candidacy for paratransgenic applications aimed at disrupting malaria transmission. This work provides the first integrated culture-NGS baseline of An. stephensi microbiota from India, offering essential insight for microbiome-based vector control strategies. Thu, 01 Jan 2026 00:00:00 GMT http://irgu.unigoa.ac.in/drs/handle/unigoa/7818 2026-01-01T00:00:00Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7816 Biopolymeric chitosan/ZnO-nanocomposite films from pomegranate peels for sustainable and functional food packaging Sangodkar, V.; Vaidya, M.; Ayyanar, M.; Prabhu, S.; Nadaf, S.; Naik, A.V.; Gurav, N.; Kumbhar, P.; Kharkar, P.; Gurav, S. Chitosan (CS), a biopolymer derived from chitin, is well known for its biodegradability and significant antimicrobial, photocatalytic, and UV-protective properties, making it an intriguing candidate for sustainable and active food packaging solutions. In response to rising environmental concerns and the demand for sustainable food packaging, this study investigates the eco-friendly synthesis of CS-conjugated Punica granatum (PG)-derived zinc oxide nanocomposites (PG-ZnONCs) for use in food packaging applications. A quality-by-design approach was employed to identify optimal conditions that maximize the desired properties of the nanocomposite films, ensuring a robust and efficient formulation process. Nanoparticle and nanocomposite preparation was confirmed by monitoring colour change and validated by UV-visible spectroscopy. X-ray diffraction, SEM, and TEM analyses confirmed the crystallite structures of the particles, with particle sizes of 112.3 nm and 160.8 nm, polydispersity indices of 0.182 and 0.215, and zeta potentials of -21.98 mV and - 10.6 mV, indicating stability. The successful application of DOE (Design of Experiments) ensured a robust and efficient formulation process, contributing to the high-quality characteristics of the final product. PG-ZnONPs and PG-CS/ZnONCs demonstrated strong antioxidant activity, effectively scavenging radicals in DPPH and ABTS assays, and exhibited potent antibacterial effects against foodborne pathogens. The PG-CS/ZnONC films (2.5 percent, 5 percent, and 7.5 percent) exhibit excellent mechanical, thermal, and barrier properties, thereby extending the shelf life of fresh foods. Incorporating Alizarin (AZ) as a pH-responsive indicator enabled real-time freshness monitoring. The PG-7.5 percent NC film preserved Solanum lycopersicum (cherry tomatoes) for 16 days and Stolephorus indicus (Indian anchovy) for 9 days, compared to 4 days for uncoated samples. Overall, PG-CS/ZnONC films, particularly with AZ for smart monitoring, present a promising solution for sustainable food packaging, enhancing food preservation while reducing waste. Thu, 01 Jan 2026 00:00:00 GMT http://irgu.unigoa.ac.in/drs/handle/unigoa/7816 2026-01-01T00:00:00Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7812 Bioremediation of chromium by Oscillatoria pseudogeminata: growth dynamics, metal uptake, and physiological responses Chahal, S.; Chanekar, T.; Bhandari, R. Hexavalent chromium, Cr(VI), is a highly toxic heavy metal that disrupts metabolic processes and threatens aquatic ecosystems. Cyanoremediation using metabolically active cyanobacteria for heavy-metal sequestration and detoxification is a sustainable, eco-friendly remediation approach. The present study evaluated the Cr(VI) removal efficiency and physiological responses of an indigenously isolated freshwater cyanobacterium, Oscillatoria pseudogeminata, under different Cr(VI) concentrations (2, 5, 7, and 10 ppm). Growth performance, photosynthetic pigments, oxidative stress markers, antioxidant responses, and chromium uptake were assessed to determine cellular responses to metal stress. Increasing Cr(VI) concentrations caused a concentration-dependent decline in growth, biomass accumulation, and pigment content, indicating impairment of photosynthetic and metabolic processes. In contrast, oxidative stress indicators and antioxidant defense responses, including malondialdehyde accumulation, superoxide dismutase activity, and proline content, were significantly elevated at lower Cr(VI) levels (2 and 5 ppm), reflecting activation of cellular defense mechanisms. These responses declined at higher concentrations, suggesting enzyme inhibition and severe metal-induced oxidative damage. Scanning electron microscopy revealed morphological alterations in treated filaments, while atomic absorption spectroscopy confirmed significant Cr(VI) absorption by the cyanobacteria, with removal efficiencies ranging from 48 to 60 percent. Overall, Oscillatoria pseudogeminata demonstrates notable chromium tolerance and biosorption capacity, highlighting its remediation potential for treating chromium-contaminated water. Thu, 01 Jan 2026 00:00:00 GMT http://irgu.unigoa.ac.in/drs/handle/unigoa/7812 2026-01-01T00:00:00Z http://irgu.unigoa.ac.in/drs/handle/unigoa/7801 Efficacy of nonantimicrobial drugs against Enterococcus faecalis using confocal laser scanning microscopy - An in vitro study Ferrao, T.M.; Ataide, I.; Lambor, R.; Kashyap, S.; Biswas, S.; Salkar, K.S.; Charya, L.S. Enterococcus faecalis is a key contributor to persistent endodontic infections and often shows resistance to conventional medicaments such as calcium hydroxide. Growing antimicrobial resistance has led to interest in repurposing nonantibiotic drugs such as nonsteroidal anti-inflammatory drugs and proton-pump inhibitors that have shown promising antimicrobial effects against E. faecalis. The study aimed to evaluate the in vitro antibiofilm activity of different combinations of nonantimicrobial drugs with and without calcium hydroxide against E. faecalis. Thu, 01 Jan 2026 00:00:00 GMT http://irgu.unigoa.ac.in/drs/handle/unigoa/7801 2026-01-01T00:00:00Z